This growth is impressive, but if the U.S. is to transition to the low-carbon, resilient, and sustainable electricity system of the future outlined in RMI’s Reinventing Fire, we need to install four times more solar capacity annually than we’re currently doing, for the next forty-odd years, with most of the installs coming in the distributed market (residential and commercial rooftops). If we’re going to do that, we need to make distributed solar cheaper, and do so quickly.

PV soft costs now dominate the equation

Between 2008 and 2012, the price of sub-10-kilowatt (mainly residential) rooftop systems decreased 37 percent. However, over 80 percent of that cost decline is attributed to decreasing solar PV module costs. With module and other hardware prices expected to level off in the coming years (and in the near term, actually increase), further market growth will be highly dependent on additional reductions in the remaining “Balance of System” costs, otherwise known as “soft costs.”

Soft costs account for 50–70 percent of the total cost of a rooftop solar system in the U.S. today. These soft costs include installation labor; permitting, inspection, and interconnection; customer acquisition; and other costs (margin, financing costs, and additional fixed administrative and other transactional cost). Setting aside those “other” costs, soft costs for U.S. residential systems are around $1.22 per watt of PV, while German soft costs average $0.33 per watt. That’s one heck of a spread. How does Germany do it, and how can U.S. installers approach or even surpass those numbers?

SIMPLE BoS project searches for answers

RMI and other groups such as the U.S. DOE, National Renewable Energy Laboratory (NREL), Lawrence Berkeley National Laboratory (LBNL), Clean Power Finance, and the Vote Solar Initiative have done great work on the issue over the past several years through benchmarking and other analysis on these various soft costs. However, such data remains relatively sparse in comparison to hardware market analysis. The U.S. solar industry has known that German installers are able to install rooftop solar systems at less than half our cost. But we haven’t been able to discern, at the detailed level of specific worker actions, why. Until now.

The SIMPLE BoS team implemented a time-and-motion methodology for evaluating the PV installation process, collecting data on PV installations in both countries.

Ample opportunities to reduce installation costs

The results indicated that U.S. installers participating in the SIMPLE BoS project incur median installation costs of $0.49/W, compared to a benchmarked median cost of $0.18/W for participating German installers. The figure below shows the comparative costs of each component of the PV installation process in the U.S. and Germany, respectively, looking at four categories of installation-related costs: racking & mounting, pre-install, electrical, and non-production.

In addition to providing cost details on the PV installation process, our report outlines several enabling factors from German and leading U.S. installers that can be disseminated throughout the U.S. market. These opportunities range widely in complexity and impact, from redesigning the base installation process and preparing rails on the ground, to implementing a one-day installation process and PV-ready electrical circuits. We’ve shown below the potential impact in $/W of these solutions and how difficult it would likely be to implement them widely the U.S.

In addition to highlighting specific opportunities for cost reduction in the U.S., our report also draws upon collected data and analysis to outline one potential pathway for U.S. installers to reduce installation labor costs by up to 64%—potentially undercutting German installation labor costs when relative differences in wages are taken into account. This pathway will not be realized overnight. It requires serious product innovation, uniform adoption of best practices, and a move to one-day installations from the average 3–5-day installation process that’s common for U.S. installers today.

We hope this report and all follow-on work under the SIMPLE BoS project will help the U.S. industry continue to reduce solar PV costs and enable the widespread, cost-effective deployment of residential solar PV systems.

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Showing 1-3 of 3 comments

December 19, 2013

I've only read this summary and am curious to study the complete report. German installers are facing several disadvantages over the US installers, incl. twice the fuel and energy cost, 19% VAT, higher social taxes and benefits (incl. three times the vacation days), etc. So this report comes as a real surprise to me. Has it been lack of competition that allowed US installers to charge four times the soft cost? 1 day installations in Germany vs. 3-5 days in the US is huge assuming we are comparing apples to apples. No more sun bathing on the roof, folks, let's get to work!

We also have more choices and better panels. The California Sunpower panels are almost twice as efficient as any in the world. We also have Tesla and an Electric Vehicle run off solar is about $1 of electric vs a gallon of gas.

Germans Installers also have advantages, especially from operating in a larger & more mature market. In addition there is better infrastructure & shorter distances between population/commercial hubs.

So in Germany there are not only more clients within reach, but also more solar industry supplier that offer all the equipment for installations at any given time.

For example in Germany installer might rent a specialized forklift/mobile crane to get alot of panels & stuff on top of a large commercial rooftop. I saw a video from a project in the US (New York City) where they had to put up a typical crane used in construction.

Not only do I asume that renting those is more expensive, but they also take more time / permits to assemble / disassemble.

In additon there are specialized solar installer teams, who have done almost nothing but build large systems all over europe (I assume) for years. They are sort of the A-Team of projects.... experienced, fast and for hire. ;-)